deadlock

问题 I am working on a C++ project, which uses Google Pub/Sub. As there is no native support for Google Pub/Sub in C++, I am using it through gRPC. Thus, I have generated corresponding pubsub.grpc.pb.h, pubsub.grpc.pb.cc, pubsub.pb.h and pubsub.pb.cc files via protoc. I wrote a lightweight wrapper-class, for subscription management. Class basically creates a new thread and starts listening for new messages. Here is the code example (code was built based on this question): class Consumer { public:

问题 I'm facing a deadlock, my code structure is similar to this: private delegate void UpdateControlDelegate(string value); public void UpdateControl(string value) { if (txtAddress.InvokeRequired) { txtAddress.Invoke(new UpdateControlDelegate(UpdateControl), value); } else { txtAddress.Text = value; // This is in GroupBox1 txtValue.Text = value; // This is in GroupBox2 } } class ThreadHandler { List<string> _list = new List<string>(); object _criticalSection = new object(); public ThreadHandler()

问题 Following up on https://stackoverflow.com/a/16553083/14731... I understand that it is important to maintain a consisting locking order for tables in order to reduce the frequency of deadlocks, and that this affects both UPDATE and SELECT statements [1]. But, does the same hold true for read-only rows? If a row is populated once at initialization time and no one modifies it ever again, does it really matter what order we access it? Given two transactions: T1, T2 and two read-only rows R1, R2

问题 As I understand it, the typical case of a deadlock involving row-locking requires four SQL statements. Two in one transaction to update row A and row B, and then a further two in a separate transaction to update the same rows, and require the same locks, but in the reverse order. Transaction 1 gets the lock on row A before transaction 2 can request it, transaction 2 gets the lock on row B before transaction 1 can get it, and neither can get the remaining required locks. One or either

问题 As I understand it, the typical case of a deadlock involving row-locking requires four SQL statements. Two in one transaction to update row A and row B, and then a further two in a separate transaction to update the same rows, and require the same locks, but in the reverse order. Transaction 1 gets the lock on row A before transaction 2 can request it, transaction 2 gets the lock on row B before transaction 1 can get it, and neither can get the remaining required locks. One or either

问题 I can prevent deadlock for Result call for async Task in sync action method of controller using both: ConfigureAwaits(false) on Task or using Task.Run . In both cases async method will be completed on thread from threadpool. Controller source: public class TestController : Controller { /// <summary> /// Thread from threadpool will be used to finish async method. /// </summary> public string TaskRun() { return Task.Run(GetStatus).Result + " <br/> " + Thread.CurrentThread.ManagedThreadId + " -

问题 I need to understand how this is possible, i.e. I would like to understand mechanics of this. Victim process is a big union-type query involves about 6 tables (Entity Frameworks) Process on a right is an insert/update batch consisting of multiple statements. I can't give SQL since they truncated in deadlock event. I've seen deadlocks involving 2/3 tables and write operations, but I can't interpret this one. What happening? I see index involved, this is valid index - I need it. I get this

问题 When I run my jvmti agent with a java program, it seems that jvm encounters a deadlock. In my jvmti agent, I create a single raw monitor in Agent_OnLoad() and enter that lock at the beginning of every callback function and exit that lock at the end of every callback functions. I don't know the reason of this deadlock. Is there any other possibilities of deadlocks in jvmti agents? thanks. 回答1: Yes, there is a possibility of deadlocks in JVMTI Agent. The JVMTI Reference states: The same thread

问题 I asked a similar question the other day but wasn't satisfied with the response, mainly because the code I supplied had some issues that people focused on. Basically, what is the best practice for locking private members in Java? Assuming each private field can only be manipulated in isolation and never together (like in my Test class example below), should you lock each private field directly (example 1), or should you use a general lock object per private field you wish to lock (example 2)?

问题 I'm setting up a test case to prove a certain deadlock scenario and require some insight on what is going on. I have a heap table, conventiently called HeapTable. This table is updated by 2 transactions simulateously. Transaction 1: BEGIN TRAN UPDATE HeapTable SET FirstName = 'Dylan' WHERE FirstName = 'Ovidiu'; WAITFOR DELAY '00:00:15'; UPDATE HeapTable SET FirstName = 'Bob' WHERE FirstName = 'Thierry'; ROLLBACK TRANSACTION Transaction 2: BEGIN TRAN UPDATE HeapTable SET FirstName = 'Pierre'